1. Field of the Invention
The present invention relates to an air guide structure for a saddle type vehicle that suitably guides air to the rear of the vehicle with respect to a windscreen for protection from a flow of air against the vehicle.
2. Description of Background Art
A saddle type vehicle may include a windscreen for protecting a rider against a flow of air. During operation of the vehicle, a negative pressure is generated behind the windscreen on the vehicle. Therefore, a flow of air is caught up behind the windscreen on the vehicle by the negative pressure. Thus, the windscreen effect is degraded or air noise is liable to be generated. In addition, the rider who is positioned behind the windscreen on the vehicle is influenced by the negative pressure. Therefore, a countermeasure is taken to reduce the negative pressure by guiding air to the rear of the windscreen on the vehicle.
An air guide structure for a saddle type vehicle is known wherein an inlet port for a flow of air is provided below the windscreen and an air guide path is formed between the windscreen and the vehicle body such that the flow of air is guided to the rear side of the windscreen by the air guide path. See, for example, Japanese Patent Laid-Open No. 2007-176297.
In this air guide structure, a flow of air passes the air guide path from the inlet port and flows to the rear side of the windscreen from an outlet port.
Since the a flow of air is distributed to the overall area on the rear side of the windscreen in the vehicle widthwise direction through use of a straightening plate or depending upon the position of through-holes, the negative pressure over a wide range behind the windscreen is reduced.
When the influence of the negative pressure behind the windscreen described above is observed, it was found that the influence at a central portion of the rider in the vehicle widthwise direction is most significant. If a flow of air is guided to flow such that it is spread over the overall range in the vehicle widthwise direction behind the windscreen as in Japanese Patent Laid-Open No. 2007-176297, a sufficient negative pressure reduction effect for the rider cannot sometimes be obtained.